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Nokogiri NULL Pointer Dereference

High severity GitHub Reviewed Published Jan 17, 2019 to the GitHub Advisory Database • Updated Dec 4, 2025

Package

bundler nokogiri (RubyGems)

Affected versions

< 1.8.5

Patched versions

1.8.5

Description

A NULL pointer dereference vulnerability exists in the xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when parsing an invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case. Applications processing untrusted XSL format inputs with the use of the libxml2 library may be vulnerable to a denial of service attack due to a crash of the application.

References

Published by the National Vulnerability Database Jul 19, 2018
Published to the GitHub Advisory Database Jan 17, 2019
Reviewed Jun 16, 2020
Last updated Dec 4, 2025

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(95th percentile)

Weaknesses

NULL Pointer Dereference

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Learn more on MITRE.

CVE ID

CVE-2018-14404

GHSA ID

GHSA-6qvp-r6r3-9p7h

Source code

No known source code
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